Ultimately Periodic Words of Rational w-Languages. - Hugues Calbrix; Maurice Nivat; Andreas Podelski (MFPS, 1993)

Prefix and Period Languages of Rational omega-Languages. - Hugues Calbrix; Maurice Nivat (Developments in Language Theory, 1995)

A String-Rewriting Characterization of Muller and Schupp's Context-Free Graphs. - Hugues Calbrix; Teodor Knapik (FSTTCS, 1998)

Thue Specifications and Their Monadic Second-order Properties. - Teodor Knapik; Hugues Calbrix (Fundam. Informaticae, 1999)